[Peanut lectin-binding sites in gastric carcinoma and the adjacent mucosa]

The histochemical binding of fluorescein isothiocyanate conjugated peanut agglutinin (PNA) to paraffin sections of 52 cases of gastric carcinomas and their adjacent mucosa was investigated. PNA could recognize the terminal Gal and beta-D-Gal (1-3)-GalNac. A high positive rate was obtained in PNA binding to malignant cells particularly in cases of signet ring cell carcinoma and mucinous adenocarcinoma. Three characteristic patterns of PNA binding to the gastric carcinoma were identified. Type I: intracytoplasmic, covering the entire cytoplasm of the malignant cells. Type II: linear, distribution along the luminal surface of the malignant cells. Type III: only very weak reaction present in a few cells or negative. Significance of PNA binding patterns in respect of the histologic classification and differentiation degree of the gastric carcinoma are discussed. Neuraminidase digestion was noticed to enhance PNA binding only in well-differentiated adenocarcinoma and PNA receptor have no specificity for tumor.